Inside the Yorktown fortifications were most of the 7,500 British and Hessian troops commanded by Cornwallis.  A smaller contingent was defending Gloucester Point, a mile across the York River on the east bank.

Cornwallis began withdrawing from his outer defenses at Yorktown on September 29 when he received the message from Clinton that the British fleet would soon be returning to break the siege.  The Americans and French moved forward to the British outer defenses and strengthened them for their assault.

The first shots were fired at the British October 9.  The first siege line -- begun the night of October 6 -- was established about 800 yards from the British defenses.  The night of October 11 a second siege line was begun closer to British positions.